Priming system for infusion devices

ABSTRACT

Priming systems and infusion assemblies are provided. For example, a priming system comprises a priming conduit having a priming portion and a pressure portion. The priming portion is in fluid communication with a first fluid source, with an inlet and an outlet for ingress and egress of a first fluid from the first fluid source. The pressure portion is in fluid communication with a second fluid source connected by a connector. Disposed within the priming conduit are a biasing member and a valve having an open position and a closed position. The biasing member is in operable communication with the valve to urge the valve into the closed position such that the valve defaults to the closed position. The open position allows the first fluid to flow from the inlet to the outlet and the closed position prevents the first fluid from flowing from the inlet to the outlet.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national phase of and claims priority toPCT/US2017/040806, filed Jul. 6, 2017, the contents of which areincorporated herein by reference thereto.

FIELD

The present invention relates to fluid dispensing apparatus and pertainsparticularly to features for priming components of infusion assemblies.

BACKGROUND

In instances of severe pain, infection, and other medical ailments, ithas been proven beneficial to administer a continuous flow of medicinalfluid to a patient through a catheter-based system. There are many typesof medicinal fluids that can be administered in this manner including,but not limited to, insulin, analgesics, and antibiotics. Often,patients are intravenously supplied with the medicinal fluid, e.g., apharmaceutically active liquid, at a controlled rate over a long periodof time. The medicinal fluid also may be delivered to a patient'sintramuscular space. Preferably, such infusion is accomplished while thepatient is in an ambulatory state. Typically, an infusion assemblyincludes an inflatable elastomeric pump forming a liquid container thatis supported by a mandrel, as well as a flow control valve or device andtubing for supply of the liquid to the patient. The walls of the pumpare forced to expand when filled with the liquid and provide pressurefor expelling the liquid.

Some infusion assemblies include components such as a flow rate selectorand/or a device for providing a bolus of the medicinal fluid. Suchcomponents must be primed before use, e.g., to remove air from areservoir in and/or the flow path through such components. Typically, abolus device includes a prime key, which lifts up a clamp that acts as aflow restrictor on tubing to fill the device such that the prime keyprevents flow restriction to the bolus device during priming of thedevice. However, such prime keys are prone to breakage and/or misusethat could allow a complete bypass of the bolus fill restrictor, whichcould result in an overdose of medication to the patient, e.g., byfailing to limit the bolus dosage over a period of time and/or byallowing a larger bolus dose than is medically indicated. On the otherhand, without bypassing such flow restrictors during priming, primingmay be a slow, cumbersome process.

Accordingly, priming systems that include one or more safety mechanismsfor preventing over-administration of medication, as well as one or morefeatures for facilitating faster or rapid priming of devices would bedesirable. Infusion assemblies incorporating such priming systems alsowould be advantageous.

SUMMARY

Aspects and advantages of the invention will be set forth in part in thefollowing description, or may be obvious from the description, or may belearned through practice of the invention.

In one aspect, the present subject matter is directed to a primingsystem. The priming system comprises a priming conduit having a primingportion and a pressure portion. The priming portion is in fluidcommunication with a first fluid source and has an inlet for ingress ofa first fluid from the first fluid source and an outlet for egress ofthe first fluid. The pressure portion includes a connector forconnecting a second fluid source such that the pressure portion is influid communication with the second fluid source. The priming systemfurther comprises a valve disposed within the priming conduit. The valvehas an open position and a closed position. The priming system alsocomprises a biasing member disposed within the priming conduit. Thebiasing member is in operable communication with the valve to urge thevalve into the closed position such that the valve defaults to theclosed position. The valve is disposed between the inlet and the outletof the priming portion such that the open position of the valve isconfigured to allow the first fluid to flow from the inlet to the outletand the closed position of the valve is configured to prevent the firstfluid from flowing from the inlet to the outlet. It will be understoodthat the priming system may be further configured with any additional oralternative features described herein.

In some embodiments, the priming conduit further comprises a stop, andthe biasing member is in contact with the stop such that the biasingmember works against the stop to control the position of the valve.Moreover, the pressure portion of the priming conduit may comprise aplug, e.g., to help build, generate, or create pressure within thepressure portion. Further, the connector may be a luer connector, andthe second fluid source may be a syringe that supplies a positivepressure to the pressure portion. In other embodiments, the second fluidsource is a vacuum source that creates a negative pressure within thepressure portion. The first fluid source may be an infusion pump.

In still other embodiments, the priming system includes a seal disposedbetween the valve and the pressure portion of the priming conduit toprevent the second fluid from flowing into the priming portion. Thevalve may be a piston and the seal an O-ring that extends about thepiston in contact with an inner surface of the pressure portion of thepriming conduit. In some embodiments where the valve is a piston, thepiston valve has a surface area, as well as a varying diameter tominimize the surface area in contact with the priming conduit.

In another aspect, the present subject matter is directed to an infusionassembly. The infusion assembly comprises an elastomeric pump configuredto provide a fluid under pressure, a flow path in fluid communicationwith the pump for providing a continuous and substantially constant flowrate of fluid from the pump, a bolus flow path for the delivery of abolus dose of the fluid, and a bolus delivery device positioned withinthe bolus flow path. The infusion assembly further comprises a primingsystem in fluid communication with the bolus flow path and configured toreceive fluid from the pump to prime the bolus delivery device. Thepriming system includes a priming conduit having a priming portion and apressure portion. The priming portion is in fluid communication with thepump and has an inlet for ingress of the fluid from the pump and anoutlet for egress of the fluid. The pressure portion includes aconnector for connecting a second fluid source such that the pressureportion is in fluid communication with the second fluid source. Thepriming system also includes a valve disposed within the primingconduit. The valve has an open position and a closed position. Thepriming system further includes a biasing member disposed within thepriming conduit. The biasing member is in operable communication withthe valve to urge the valve into the closed position such that the valvedefaults to the closed position. The valve is disposed between the inletand the outlet of the priming portion such that the open position of thevalve is configured to allow the fluid to flow from the inlet to theoutlet and the closed position of the valve is configured to prevent thefluid from flowing from the inlet to the outlet. It will be appreciatedthat the priming system may be further configured with any additional oralternative features described herein.

In some embodiments, a flow restrictor is positioned within the bolusflow path, and the priming conduit bypasses the flow restrictor suchthat the inlet of the priming portion is in fluid communication with thebolus flow path upstream of the flow restrictor and the outlet of thepriming portion is in fluid communication with the bolus flow pathdownstream of the flow restrictor. Further, the second fluid source mayprovide a second fluid to the pressure portion to move the valve fromthe closed position to the open position. In some embodiments, thepriming conduit also comprises a stop, and the biasing member is incontact with the stop such that the biasing member works against thestop to control the position of the valve.

In still other embodiments, the connector is a luer connector. Thesecond fluid source may be a syringe that supplies a positive pressureto the pressure portion. In other embodiments, the second fluid sourceis a vacuum source that creates a negative pressure within the pressureportion.

In further embodiments, a seal is disposed between the valve and thepressure portion of the priming conduit to prevent the second fluid fromflowing into the priming portion. The valve may be a piston and the sealan O-ring that extends about the piston in contact with an inner surfaceof the pressure portion of the priming conduit. Moreover, in embodimentsin which the valve is a piston, the piston valve may have a surfacearea, as well as a varying diameter to minimize the surface area incontact with the priming conduit.

These and other features, aspects, and advantages of the presentinvention will become better understood with reference to the followingdescription and appended claims. The accompanying drawings, which areincorporated in and constitute a part of this specification, illustrateembodiments of the invention and, together with the description, serveto explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth in the specification, which makes reference to the appendedfigures, in which:

FIG. 1 is a schematic view of an infusion assembly having a bolusdelivery device according to an exemplary embodiment of the presentsubject matter.

FIG. 2 is a schematic view of a priming system for priming the bolusdelivery device of the infusion assembly of FIG. 1, with the primingsystem in its default closed state, according to an exemplary embodimentof the present subject matter.

FIG. 3 is the schematic view of the priming system of FIG. 2, with thepriming system in an open state.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention,one or more examples of which are illustrated in the drawings. Eachexample is provided by way of explanation of the invention, notlimitation of the invention. In fact, it will be apparent to thoseskilled in the art that various modifications and variations can be madein the present invention without departing from the scope or spirit ofthe invention. For instance, features illustrated or described as partof one embodiment can be used with another embodiment to yield a stillfurther embodiment. Thus, it is intended that the present inventioncovers such modifications and variations as come within the scope of theappended claims and their equivalents.

Moreover, the particular naming of the components, capitalization ofterms, the attributes, data structures, or any other programming orstructural aspect is not mandatory or significant, and the mechanismsthat implement the invention or its features may have different names,formats, or protocols. Also, the particular division of functionalitybetween the various components described herein is merely exemplary andnot mandatory; functions performed by a single component may instead beperformed by multiple components, and functions performed by multiplecomponents may instead performed by a single component.

Further, the detailed description uses numerical and letter designationsto refer to features in the drawings. Like or similar designations inthe drawings and description have been used to refer to like or similarparts of the invention. As used herein, the terms “first,” “second,” and“third” may be used interchangeably to distinguish one component fromanother and are not intended to signify location or importance of theindividual components.

Referring to the drawings, FIG. 1 provides a side view of an infusionassembly, e.g., for dispensing a fluid to a patient, according to anexemplary embodiment of the present subject matter. As shown, theexemplary infusion assembly 100 includes an elastomeric pump 102 havingan upper support member 104 and a lower support member 106. Infusionassembly 100 defines an axial direction A, and lower support member 106is spaced apart from upper support member 104 along the axial directionA.

More particularly, pump 102 defines a reservoir that serves as apressurized fluid source, holding medicinal fluid, such as localanesthetics, and providing a source of fluid under pressure. Pump 102forces the medicinal fluid through a tubing or conduit 108. Conduit 108forms a continuous flow path 110 for delivery of the medicinal fluidinto a wound site nerve bundle or the blood stream of a patient P. Inthe depicted exemplary embodiment, conduit or tubing 108 defines anoutlet 112 connecting the continuous flow path 110 to a catheter 114that delivers the medicinal fluid to patient P. In such embodiments,conduit 108 and catheter 114 may together define continuous flow path110 from pump 102 to patient P.

Further, in some embodiments, infusion assembly 100 may be configured toprovide for bolus delivery. In such configurations, conduit 108 maysplit into a continuous or primary flow path 110 and a controlled bolusflow path 140. Thus, medicinal fluid may be delivered into a wound sitenerve bundle or the blood stream of patient P from pump 102 via thecontinuous or primary flow path or from a bolus delivery device 150 viathe controlled bolus flow path.

Pump 102 preferably accommodates a volume 134 from about 100 to 500 mlof fluid under a pressure of up to approximately 30 psi. In someembodiments, the pump may hold the fluid under a pressure of about 10psi to about 30 psi and, in other embodiments, under a pressure of about15 psi to about 25 psi. More particularly, pump 102 has an inner core116 extending between upper support member 104 and lower support member106 along axial direction A. Inner core 116 is surrounded by anelastomeric bladder 118 within a housing 120. Inner core 114 preferablyhas an inlet port 122, e.g., to fill bladder 118 with fluid, and anoutlet port 124 in fluid communication with conduit 108, e.g., todispense the fluid from bladder 118 to patient P through flow path 110.Fluid is held under pressure within elastomeric bladder 118 and flowsfrom elastomeric bladder 118 into conduit 108 through outlet port 124,preferably flowing at a controlled and predictable rate. Alternatively,conduit 108 may be sized to serve as a flow restrictor. Further,elastomeric bladder 118 preferably is constructed from a resilientmaterial that may comprise a variety of elastomeric compositions wellknown in the art, including vulcanized synthetic polyisoprenes, naturallatex, natural rubber, synthetic rubber, silicone rubber, or the like.

Exemplary pumps are described in U.S. Pat. Nos. 7,959,623 and 5,254,481,which are hereby incorporated by reference. A variety of otherconventional pumps also may be used. For example, the pumps described inU.S. Pat. Nos. 5,080,652 and 5,105,983, which are hereby incorporated byreference, may be used. As will be understood by those of skill in theart, other suitable electronic or mechanical pumps offered by othermanufacturers may be used as well.

Continuing with FIG. 1, an optional clamp 126 is positioned in flow path110 downstream from pump 102. Clamp 126 can compress conduit 108 suchthat fluid flow from pump 102 through flow path 110 is occluded. Suchocclusion is advantageous, e.g., for the transportation and preparationof infusion assembly 100 as described herein. An exemplary clamp 126 isdescribed in U.S. Pat. No. 6,350,253, which is hereby incorporated byreference. However, a variety of other conventional clamps known in theindustry may be used to occlude the flow of fluid from pump 102 throughflow path 110, such as compression clamps, C clamps, roller clamps, andthe like.

An optional filter 128 downstream of clamp 126 separates the fluid fromcontaminates and other undesired particles that may be found within thefluid. Filter 128 also preferably eliminates air from fluid flow path110. One such filter 128 is described in U.S. Pat. No. 6,350,253, whichis hereby incorporated by reference. Of course, other suitable filtersrecognized in the industry may be used to capture undesired particlesand/or remove air from the system.

As further shown in FIG. 1, an optional flow regulator 130 is positionedin continuous flow path 110. Flow regulator 130 sets the continuous andsubstantially constant flow rate of fluid from pump 102 to patient P viatubing 108. In some embodiments, the flow rate may be adjusted to a ratewithin a range, e.g., within a range of about 0.5 to about 14 cubiccentimeters of fluid per hour. Flow regulator 130 may be manuallyadjustable, if desired, and provided with a dial, switch, or lever withan adjustable flow rate control display corresponding to the range offlow rates. For example, the flow rate range may be from about 1 toabout 7 or from about 2 to about 14 cubic centimeters of fluid per hoursuch that the flow rate control display includes a lowermost value of 1and an uppermost value of 7 or a lowermost value of 2 and an uppermostvalue of 14. It will be appreciated that the foregoing flow rate valuesare only exemplary, and in other embodiments, infusion assembly 100 mayhave other flow rates and the flow rate may be adjustable within anotherrange of flow rates. Alternatively, a constant flow regulator (i.e., aregulator that is not adjustable) can be employed. For example, anoptional flow regulating orifice, such as a glass orifice tube 132, maybe employed in the primary or continuous flow path 110. Moreover, inembodiments having a bolus flow path, an optional second flow regulatingorifice 146 may be employed in the bolus flow path.

The particular arrangement of clamp 126, filter 128, and flow regulator130 (or glass tube 132) described herein is merely exemplary. Theseelements, if present, may be arranged in any order, as will be easilyunderstood by those skilled in the art. Desirably, however, glassorifice tube 132 is located downstream of filter 128 when orifice tube132 and filter 128 are provided in infusion assembly 100.

In the exemplary embodiment illustrated in FIG. 1, the conduit 108splits into two flow paths, the continuous or primary flow path 110 andthe bolus flow path 140. As previously described, a bolus deliverydevice 150 is in fluid communication with the bolus flow path 140. Thebolus delivery device 150 accumulates a quantity of fluid from the bolusflow path 140 leading from the pump 102 and holds the fluid underpressure until the bolus dose is triggered by an actuator (not shown)for release into the patient P. The actuator of the bolus deliverydevice 150 may be operable by any user, such as the patient P, acaregiver, a physician, etc., to dispense a bolus dose of the medicinalfluid to the patient P.

Generally, the bolus delivery device 150 is configured to receive fluid,elastically expand to pressurize the fluid, store the pressurized fluid,and dispense the pressurized fluid while avoiding over-administration ofa medicinal fluid to the patient. Downstream from the bolus deliverydevice 150, the continuous flow path 110 and the bolus flow path 140converge into a single flow path. Further, as illustrated in FIG. 1, aclamp 142, a filter 144, and/or a flow restrictor 146, such as a flowregulating orifice, may be positioned in the bolus flow path 140upstream of the device 150. The clamp 142 can compress the flow path 140such that fluid flow from the pump 102 is occluded. Such occlusion isadvantageous, e.g., for the transportation and preparation of the fluiddelivery device. Moreover, the optional filter 144 downstream of clamp142 separates the fluid from contaminates and other undesired particlesthat may be found within the fluid, as well as preferably eliminates airfrom the bolus flow path 140. Exemplary clamps and filters that may beused for clamp 142 and filter 144 are described in greater detail abovewith respect to clamp 126 and filter 128.

The flow restrictor 146 restricts the flow of fluid to the bolusdelivery device 150, e.g., to help control the bolus refill rate. Forexample, fluid from the pump 102 refills a reservoir of the device 150following the administration of a bolus dose to the patient P. Bycontrolling the refill rate of the reservoir, the flow restrictor 146may be one feature of the bolus system that helps preventover-administration of medication to the patient, e.g., by limiting orrestricting the delivery of additional medicinal fluid to the patientwithin a time period following the administration of a bolus dose of themedicinal fluid. As shown in FIG. 1, a priming system 200 is included inparallel with the flow path 140, providing a bypass circuit around theflow restrictor 146 for faster or rapid priming of the bolus deliverydevice 150. The priming system 200 is in fluid communication with thebolus flow path 140 and is configured to receive fluid from the pump 102to prime the bolus delivery device 150.

Although described herein with respect to the bolus system of theinfusion assembly 100, it should be appreciated that the priming system200 described herein also may be used to prime infusion assembly tubingand/or other components of the infusion assembly 100, such as flowselection devices or the like. Of course, the priming system 200 may beused with other appropriate assemblies, devices, or systems as well.

Turning now to FIGS. 2 and 3, the priming system 200 will be describedin greater detail. As shown in FIG. 2, the priming system 200 comprisesa priming conduit 202 that has a priming portion 204 and a pressureportion 206. The priming portion 204 is in fluid communication with afirst fluid source 208 that provides a first fluid F₁ to the primingsystem 200. The priming portion 204 has an inlet 210 for ingress of thefirst fluid F₁ from the first fluid source 208 and an outlet 212 foregress of the first fluid F₁ from the priming system 200. In thedepicted embodiment, the first fluid source 208 is the pump 102, whichprovides medicinal fluid to the bolus flow path 140 such that themedicinal fluid is the first fluid F₁ in the exemplary embodiment. Inother embodiments, the first fluid source 208 and first fluid F₁ may beany suitable fluid source and fluid provided by such fluid source. Thefirst fluid F₁ flows into the bolus flow path 140 and, under certainconditions described in greater detail below, bypasses the flowrestrictor 146 by flowing into the priming portion 204 of the primingsystem 200. The first fluid F₁ may then flow to the bolus deliverydevice 150, e.g., to prime the device 150 and its associated tubing.

The pressure portion 206 of priming system 200 is in fluid communicationwith a second fluid source 214 that provides a second fluid F₂ to thepriming system 200. More particularly, the pressure portion 206 includesa connector 216 for connecting the second fluid source 214 to thepressure portion. In the depicted embodiment, the connector 216 is aluer connector and the second fluid source 214 is a syringe thatsupplies a second fluid F₂ such as saline or the like, but in otherembodiments, other types of connectors 216, fluid sources 214, andsecond fluids F₂ also may be used. For example, the second fluid source214 may be a vacuum source that generates or supplies a vacuum withinthe pressure portion 206. Thus, in various embodiments, the second fluidsource 214 and second fluid F₂ may generate either a positive pressureor a negative pressure within the pressure portion 206 of the primingconduit 202.

As shown in FIGS. 2 and 3, a gate or valve 218 is disposed within thepriming conduit 202. In the illustrated embodiment, the valve 218 is apiston or plunger disposed in the pressure portion 206 of the primingconduit 202, but the valve 218 may have any suitable configuration.Further, the valve 218 has a closed position, as shown in FIG. 2, and anopen position, as illustrated in FIG. 3. In the depicted embodimentwhere valve 218 is a piston, the piston 218 has a varying diameter d;more particularly, the piston 218 has a first diameter d₁ and a seconddiameter d₂. The first diameter d₁ is in contact with an inner surface220 of the priming portion 206, and the second diameter d₂ is smallerthan the first diameter d₁. As such, the segments of the piston 218having the second diameter d₂ do not contact the inner surface 220 ofthe priming portion 206.

As illustrated in FIGS. 1-3, the pressure portion 206 of the primingconduit 202 intersects the priming portion 204 at an intersection 222.The valve 218 spans the intersection 222 between the priming andpressure portions 204, 206 such that the closed and open positions ofthe valve 218 control whether the first fluid F₁ may flow from the inlet210 to the outlet 212 of the priming portion 204. That is, the valve 218is disposed between the inlet 210 and the outlet 212 of the primingportion 204 such that the open position of the valve 218 is configuredto allow the first fluid F₁ to flow from the inlet 210 to the outlet212, and thereby on to the bolus delivery device 150 via the bolus flowpath 140, and the closed position of the valve 218 is configured toprevent the first fluid F₁ from flowing from the inlet 210 to the outlet212.

More specifically, for the illustrated piston embodiment, the firstdiameter d₁ of the valve 218 spans the intersection 222 when the valve218 is in the closed position. Because the segments of the valve 218having the first diameter d₁ contact the inner surface 220 of thepriming portion 206 of the priming conduit 202, the valve 218 preventsthe first fluid F₁ from flowing across the intersection 222, i.e., thevalve 218 blocks the intersection 222 and thereby prevents the firstfluid F₁ from flowing from the inlet 210 of the priming portion 204 tothe outlet 212 of the priming portion 204. However, when the valve 218is in the open position, a segment of the valve 218 having the seconddiameter d₂ spans the intersection 222. Because the second diameter d₂of the valve 218 is smaller than the first diameter d₁, the seconddiameter d₂ segment of the valve 218 does not block the intersection 222of the priming and pressure portions 204, 206, and the first fluid F₁may flow from the priming portion inlet 210 around the valve 218 to thepriming portion outlet 212, where the first fluid F₁ reenters the bolusflow path 140 to flow on to the bolus delivery device 150 and any otherdownstream components of the infusion assembly 100.

As illustrated in FIGS. 2 and 3, the priming system 200 includes abiasing member 224, such as a spring or the like, disposed within thepriming conduit 202. The biasing member 224 is in operable communicationwith the valve 218 to urge the valve into the closed position shown inFIG. 2. Further, the priming conduit 202 comprises a stop 226, and thebiasing member 224 is in contact with the stop 226 such that the biasingmember 224 works against the stop 226 to control the position of thevalve 218. As shown in FIG. 2, the biasing member 224 pushes against thestop 226 to urge the valve 218 into the closed position. As depicted inFIG. 3, when the second fluid F₂ from the second fluid source 214 isintroduced into the pressure portion 206 of the priming conduit 202, thevalve 218 pushes the biasing member 224 against the stop 226 as thevalve 218 moves to the open position. That is, the second fluid F₂applies sufficient pressure to the valve 218 to overcome the force ofthe biasing member 224 and move the valve until a valve segment havingthe second diameter d₂ is positioned within the intersection 222 of thepriming and pressure portions 204, 206 of the priming conduit 202. Aspreviously described, the segment of the valve 218 having the seconddiameter d₂ does not completely block the intersection 222, such thatthe first fluid F₁ may flow past the valve 218 and through the outlet212 of the priming portion 204. Thus, the valve 218 in the exemplaryembodiment functions as a spring-loaded check valve that is opened with,e.g., water pressure supplied by the second fluid F₂ and second fluidsource 214. However, as described above, the second fluid source 214 andsecond fluid F₂ also may utilize a negative pressure, such as a vacuum,to manipulate the position of valve 218. For instance, rather thanpushing the valve 218 using a positive pressure from the second fluidsource 214 and/or second fluid F₂, the valve 218 may be pulled using anegative pressure from the second fluid source 214 and/or second fluidF₂.

The piston-style valve 218 of the embodiment illustrated in FIGS. 2 and3 has a segment having the second diameter d₂ between two segments thateach have the first diameter d₁. As such, when the valve 218 is in theopen position as shown in FIG. 3, the first fluid F₁ flows past thevalve 218 but only within the priming portion 204 of the priming conduit202. That is, the first fluid F₁ does not flow into the pressure portion206 of the conduit 202. Similarly, the valve 218 and biasing member 224are configured such that the valve 218 does not open to an extent toallow the second fluid F₂ to flow into the priming portion 204. In someembodiments, the priming system 200 comprises a seal 228 disposedbetween the valve 218 and the pressure portion 206 of the primingconduit 202 to prevent the second fluid F₂ from flowing into the primingportion 204, which also helps prevent the first fluid F₁ from flowinginto the pressure portion 206. The seal 228 may be an O-ring thatextends about the piston-style valve 218, as shown in the exemplaryembodiment, and that is in contact with the inner surface 220 of thepressure portion 206. Of course, some embodiments may utilize more thanone seal 228, such as more than one O-ring or a variety of differenttypes of seals.

As described above, the valve 218 may have a varying diameter d;specifically, the exemplary valve 218 has a first diameter d₁ and asecond diameter d₂ that is smaller than the first diameter d₁. Theposition of the first and second diameters d₁ and d₂ with respect to theintersection 222 between the priming and pressure portions 204, 206 ofthe priming conduit 202 determine whether the valve 218 is open,permitting the first fluid F₁ to flow through the priming portion 204,or closed, preventing the first fluid F₁ from flowing through thepriming portion 204. However, the varying diameter d of the valve 218also varies the surface area of the valve 218 in contact with the innersurface 220 of the pressure portion 206. More particularly, the valve218, configured as a piston in the embodiment of FIGS. 2 and 3, has asurface area A_(S). The length of each segment of the valve 218 having adiameter sufficient to contact the inner surface 220 of the pressureportion 206, i.e., the first diameter d₁ in the exemplary embodiment,determines the surface area A_(S) of the valve 218 that is in contactwith the inner surface 220. The varying diameter of the valve 218, e.g.,the different diameters and the length of each segment of a givendiameter, may be chosen to minimize the surface area A_(S) in contactwith the priming conduit 202, specifically the pressure portion 206 ofthe priming conduit 202. By minimizing the surface area A_(S) in contactwith the priming conduit 202, friction between the valve 218 and thepriming conduit 202 may be minimized, which may help the valve 218 movebetween the closed and open positions.

As further illustrated in FIGS. 1-3, the pressure portion 206 of thepriming conduit 202 may be generally Y shaped, with a stem 230 a and twoarms 230 b, 230 c. The stem 230 a intersects the priming portion 204,and the stop 226, biasing member 224, and valve 218 are disposed withinthe stem 230 a. The first arm 230 b includes the connector 216, to whichthe second fluid source 214 may be attached, and the second arm 230 cincludes a plug 232. The plugged second arm 230 c provides additionalarea within the pressure portion 206 to build sufficient pressure withsecond fluid F₂ to open the valve 218, i.e., when second fluid F₂supplies a positive pressure within the pressure portion 206. In someembodiments, the second arm 230 c and plug 232 may be omitted. Forexample, the pressure portion 206 of the priming conduit 202 may have ashape and/or size such that sufficient pressure is built up with thepressure portion 206 when the second fluid F₂ is inserted into thepressure portion 206 without the need for the second arm 230 c.

With the valve 218 opened by the positive or negative pressure of thesecond fluid F₂ supplied by the second fluid source 214 as shown in FIG.3, fluid (i.e., first fluid F₁) from the pump 102 (i.e., first fluidsource 208) flows through the priming portion 204 of the priming conduit202 and on through the bolus delivery device 150, which preferablyincludes a reservoir for receipt of a volume of fluid from the pump 102.As such, the fluid F₁ displaces air within the device 150, as well asany other devices downstream of the priming system 200. Once the fluidhas flowed through the device 150, the second fluid source 214 may beremoved, such that the valve 218 moves to the closed positionillustrated in FIG. 2, and the fluid F₁ flows through the flowrestrictor 146, rather than the priming system 200, to fill thereservoir of the device 150. At this point, the bolus delivery device150, and any other devices downstream of the priming system 200, isprimed, and the connector 216 may be removed from the priming portion206 to prevent bypassing of the flow restrictor 146 as a second fluidsource 214 cannot be positioned in fluid communication with the primingconduit 202 to supply a second fluid F₂ to pressurize and open the valve218. That is, the priming system 200 permits priming of, e.g., the bolusdelivery device 150 in a faster manner or reduced amount of time bybypassing the flow restrictor 146, which controls the flow rate of themedicinal fluid from pump 102 to the bolus delivery device 150. As such,the medicinal fluid reaches the bolus delivery device 150 faster whenthe fluid travels through the priming system 200 rather than the flowrestrictor 146. If the medicinal fluid is permitted to flow through thepriming system 200 to completely fill and/or refill the bolus deliverydevice 150, an excess or overdose of medicinal fluid could be providedto the patient P by not allowing a clinically sufficient time betweenbolus doses. Thus, in exemplary embodiments, the priming system 200includes features such as a removable connector 216 to help preventbypassing of the flow restrictor 146 outside of priming the bolusdelivery device 150.

The priming system 200 also may include other safety features that, inparticular, prevent bypassing the flow control provided by the flowrestrictor 146 to help prevent over-administration of medication to thepatient. For instance, the pressure required to move the valve 218 tothe open position of FIG. 3, i.e., the cracking pressure, may beselected to ensure the valve 218 stays closed until and/or only when thesecond fluid source 214 applies at least the cracking pressure to thevalve 218. As an example, the cracking pressure may be about 10 psi,such that the valve 218 opens when the pressure portion 206 of thepriming conduit 202 is pressurized by the second fluid source 214 over10 psi. It will be appreciated that the cracking pressure may beadjusted by, e.g., changing the spring rate where the biasing member 224is a spring and/or changing the dimensions of the valve 218 or othercomponents of the priming system 200. As another safety feature, thepriming conduit 202, particularly the pressure portion 206, may a microflow path to discourage and/or prevent users from sticking objects intothe pressure portion 206 to try to manually open the valve 218. That is,in some embodiments of the priming system 200, at least the pressureportion 206 may have a sufficiently small diameter such that objectscannot be inserted into the pressure portion 206 to bypass the flowrestrictor 146 by moving the valve 218 from the closed position of FIG.2 to the open position of FIG. 3. The priming system 200 may incorporateother safety features as well.

Accordingly, as described herein, a system is provided for fasterpriming of various components of an infusion assembly. In exemplaryembodiments, the priming system described herein allows faster primingof certain components of the infusion assembly by bypassing a flowrestrictor that otherwise controls the flow rate of fluid to thecomponents. However, the priming system also includes features fordiscouraging or preventing continuous and/or non-priming relatedbypassing of the flow restrictor, such that the flow rate may becontrolled per the design of the infusion system. For instance, thepriming system defaults to a closed position, such that the fluid of theinfusion assembly is permitted to flow through the priming system,bypassing the flow restrictor, upon a positive action by a user. Inparticular embodiments, the positive action may be the connection of asecond fluid source that applies pressure to a check valve controllingflow through the priming system, and the ability to connect the secondfluid source may be disabled after priming, e.g., by removing orbreaking off a connector, such that the priming system returns to itsdefault closed position and cannot be re-opened. Other benefits andadvantages of the subject matter described herein also may be realizedby those of ordinary skill in the art.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they include structural elementsthat do not differ from the literal language of the claims or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal language of the claims.

What is claimed is:
 1. A priming system, comprising: a priming conduithaving a priming portion in fluid communication with a first fluidsource, the priming portion having an inlet for ingress of a first fluidfrom the first fluid source and an outlet for egress of the first fluid,and a pressure portion including a connector for connecting a secondfluid source such that the pressure portion is in fluid communicationwith the second fluid source, and a plug; a valve disposed within thepriming conduit, the valve having an open position and a closedposition; and a biasing member disposed within the priming conduit, thebiasing member in operable communication with the valve to urge thevalve into the closed position such that the valve defaults to theclosed position, wherein the valve is disposed between the inlet and theoutlet of the priming portion such that the open position of the valveis configured to allow the first fluid to flow from the inlet to theoutlet and the closed position of the valve is configured to prevent thefirst fluid from flowing from the inlet to the outlet.
 2. The primingsystem of claim 1, wherein the priming conduit further comprises a stop,and wherein the biasing member is in contact with the stop such that thebiasing member works against the stop to control the open and closedpositions of the valve.
 3. The priming system of claim 1, wherein theconnector is a luer connector.
 4. The priming system of claim 1, whereinthe first fluid source is an infusion pump.
 5. The priming system ofclaim 1, wherein the second fluid source is a syringe supplying apositive pressure to the pressure portion.
 6. The priming system ofclaim 1, wherein the second fluid source is a vacuum source creating anegative pressure within the pressure portion.
 7. The priming system ofclaim 1, further comprising a seal disposed between the valve and thepressure portion of the priming conduit to prevent the second fluid fromflowing into the priming portion.
 8. The priming system of claim 7,wherein the valve is a piston and the seal is an O-ring extending aboutthe piston and in contact with an inner surface of the pressure portionof the priming conduit.
 9. The priming system of claim 1, wherein thevalve is a piston having a surface area, and wherein the piston has avarying diameter to minimize the surface area in contact with thepriming conduit.
 10. An infusion assembly, comprising: an elastomericpump configured to provide a fluid under pressure; a flow path in fluidcommunication with the pump for providing a continuous and substantiallyconstant flow rate of the fluid from the pump; a bolus flow path for thedelivery of a bolus dose of the fluid; a flow restrictor positionedwithin the bolus flow path; a bolus delivery device positioned withinthe bolus flow path; and a priming system in fluid communication withthe bolus flow path and configured to receive the fluid from the pump toprime the bolus delivery device, the priming system including: a primingconduit having: a priming portion in fluid communication with the pump,the priming portion having an inlet for ingress of the fluid from thepump and an outlet for egress of the fluid, and a pressure portionincluding a connector for connecting a second fluid source such that thepressure portion is in fluid communication with the second fluid source;a valve disposed within the priming conduit, the valve having an openposition and a closed position; and a biasing member disposed within thepriming conduit, the biasing member in operable communication with thevalve to urge the valve into the closed position such that the valvedefaults to the closed position, wherein the valve is disposed betweenthe inlet and the outlet of the priming portion such that the openposition of the valve is configured to allow the fluid to flow from theinlet to the outlet and the closed position of the valve is configuredto prevent the fluid from flowing from the inlet to the outlet, whereinthe priming conduit bypasses the flow restrictor such that the inlet ofthe priming portion is in fluid communication with the bolus flow pathupstream of the flow restrictor and the outlet of the priming portion isin fluid communication with the bolus flow path downstream of the flowrestrictor.
 11. The infusion assembly of claim 10, wherein the secondfluid source provides a second fluid to the pressure portion to move thevalve from the closed position to the open position.
 12. The infusionassembly of claim 10, wherein the priming conduit further comprises astop, and wherein the biasing member is in contact with the stop suchthat the biasing member works against the stop to control the open andclosed positions of the valve.
 13. The infusion assembly of claim 10,wherein the connector is a luer connector.
 14. The infusion assembly ofclaim 10, wherein the second fluid source is a syringe supplying apositive pressure to the pressure portion.
 15. The infusion assembly ofclaim 10, wherein the second fluid source is a vacuum source creating anegative pressure within the pressure portion.
 16. The infusion assemblyof claim 10, further comprising a seal disposed between the valve andthe pressure portion of the priming conduit to prevent the second fluidfrom flowing into the priming portion.
 17. The infusion assembly ofclaim 16, wherein the valve is a piston and the seal is an O-ringextending about the piston and in contact with an inner surface of thepressure portion of the priming conduit.
 18. The infusion assembly ofclaim 10, wherein the valve is a piston having a surface area, andwherein the piston has a varying diameter to minimize the surface areain contact with the priming conduit.